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I'm trying to save money to make a custom turbo for my 1993 MX3. The first thing I had to do was put a Protege engine in my car, which I did. For the custom turbo project I am having some conflicts with the fuel system, as in what to buy. I know that a fuel pump and bigger injectors are a must for the fuel setup. My problem is now I can't see why I should waste money on a apexi AFC fuel controller and a rising fuel pressure regulator. Don't they do the same thing? Can't I just get away with having one or the other instead of buying both? Am I right or wrong, Don't both of them put more fuel in the engine?

If you get the S-AFC it should take care of everything.

Wrong. Lets think about this for a moment, $150 for a rr-fpr, $300 for a S-AFC. Total is $450 usd, how much do you think a replacement engine is?? Maybe that will put your "waste of money" into perspective.

A rr-fpr will only increase fuel pressure as boost increases. It isn't needed if running a standalone but if you aren't spending the money for one then it is a very good idea. The S-AFC just changes the fuel curve to aid in making power and increase efficiency. The S-AFC will help you lean out the mixture as things tend to run rich from the factory. They don't do the same thing but teamed together make for a pretty reliable system of fuel enrichment. One big note, the S-AFC doesn't work well with our TPS, might want to look into using a MAP sensor to run the S-AFC instead.

I still haven't figured out why some of you insist on skimping on fuel systems and engine control units. Money is hard to come by, spend it wisely.

The rising fuel pressure regulator feeds the engine more fuel and the apexi afc controller feeds the engine more fuel. The only difference that I see between them is that one is manual controlled and one is electric controlled. Is it nessecery to spend the money and have both?

rite now im running a rx-7 fuel pump, 626 2.2L injectors, and boost sensitive fuel pres. reg. and i still dont have it quite rite yet. the next thing is the apxi AFC. maldo is totaly rite youv got to spend the money. im running real rich but its the only way i could get it to not ping without the AFC. check overboost . com out, thats where i got my fuel pres reg. 50 bucks US, totaly adjustable.

Originally posted by Josh:
rite now im running a rx-7 fuel pump, 626 2.2L injectors, and boost sensitive fuel pres. reg. and i still dont have it quite rite yet. the next thing is the apxi AFC. maldo is totaly rite youv got to spend the money. im running real rich but its the only way i could get it to not ping without the AFC. check overboost . com out, thats where i got my fuel pres reg. 50 bucks US, totaly adjustable.

if you get a boost sensitive timming controler(MSD makes them) then you wouldnt have to run so rich to prevent pining.

The rising fuel pressure regulator feeds the engine more fuel and the apexi afc controller feeds the engine more fuel. The only difference that I see between them is that one is manual controlled and one is electric controlled. Is it nessecery to spend the money and have both?

If you have to ask, you haven't done enough research on your project. With that in mind, I would not advise you to pursue this project until you fully understand what it is you are getting yourself into. These two devices are completely different, but yes, the goal is to provide better fueling for both. I am spending $2800usd on a TEC-III that essentially adds fuel just like the rr-fpr and the S-AFC, you tell me, is it worth it?

yah i know:) i just havent gotten one yet. i have the digital SCI and im trying to get it in. but no one knows how and i cant find a wiring diagram of the distributor insides. so i have to call msd back up and ask them to help me, but they said that they didnt know how to hook it up either on the mx 1.6 inturnal coil.and if i try to hook it up like the 2.5 then it will blow my coil they said. ill get it all working again when i get my new tranny next week.

If you are running larger injectors the AFC lets you trim them back so you dont run soo rich when you are not under boost. I have a set of 370 cc injectors and under lo throttle i had to trim the injectors back almost 40 percent to make it run correctly. I am also using a bell engineering rrfpr. Car runs EXCELLENT. No problems have have been running 10-12 pounds of boost for a few months now with no issues....*knocks on wood*

For now all I can afford is a FMU regulator to enrich my fuel. My problem exactly is that I swaped in a BP Protege motor and I am using my 1.6L SOHC ECU. I can sense that the motor is running lean and needs more fuel. What FMU pressure regulator are you guys using? Which do you recommend?

I think i'm seeing the big picture now. The FMU pressure regulator is use to richen things up and the apexi' AFC controller is use to control how rich and lean things get. Right?